Question

I am reading in a csv file in Java and, depending on the format of the string on a given line, I have to do something different with it. The three different formats contained in the csv file are (using random numbers):

833
“79, 869”
“56-57, 568”

If it is just a single number (833), I want to add it to my ArrayList. If it is two numbers separated by a comma and surrounded by quotations (“79, 869)”, I want to parse out the first of the two numbers (79) and add it to the ArrayList. If it is three numbers surrounded by quotations (where the first two numbers are separated by a dash, and the third by a comma [“56-57, 568”], then I want to parse out the third number (568) and add it to the ArrayList.

I am having trouble using str.contains() to determine if the string on a given line contains a dash or not. Can anyone offer me some help? Here is what I have so far:

private static void getFile(String filePath) throws java.io.IOException {
    BufferedReader reader = new BufferedReader(new FileReader(filePath));
    String str;

    while ((str = reader.readLine()) != null) {

        if(str.endsWith("\"")){
            if (str.contains(charDash)){
                System.out.println(str);
            }
        }

    }

}

Thanks!

Answer 1

I recommend using the version of indexOf that actually takes a char rather than a string, since this method is much faster. (It is a simple loop, without a nested loop.)

I.e.

  if (str.indexOf('-')!=-1) {
      System.out.println(str);
   }

(Note the single quotes, so this is a char, rather than a string.)

But then you have to split the line and parse the individual values. At present, you are testing if the whole line ends with a quote, which is probably not what you want.